Gun turret



Dec. 24, 1946. e. w. PONTIUS, 30., ETAL A J GUN TURRET Filed Jan. 18, 1943 7 Sheets-Sheet 2 Tia-2 NVENTORS GEORGE W I05 5mm lMflZ/V/TZ Dec. 24, 1946. G. w. PONTlUS, 30., ETAL- 2,413,114 GUN TURRET Filed Jan. 18, 1945 7 Sheets-Sheet 3 7 heets-Sheet 4 G. w. PONTIUS, 30., EIAL GUN TURRET Filed Ja 182 1943 1946- G. w. PONTIUS, 30., E TAL ,1

GUN TURRET Filed Jan. 18, 1945 '7 Sheets-Sheet 5 INVENTOR GEORGE W FONT/U5 Dec. 24, 1946. G. w. PONTIUYS, '30., EI'AL 2,413,114

IN VE N TORS the guns.

GUN BET George W. Pontius, all

, and Frank V. Kuzmitz',

South Bend, End, assignors to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application .lanuary 18, 1943, Serial No. 472,716 I i 4 Claims.

This invention relates generally to turrets and particularly to turrets of the type which may be employed in aircraft. More particularly, the invention relates to aircraft turrets which may be located in the bow or the stern of the fuselage of an aircraft for improving the defense of these vital areas.

While the invention is shown as being adapted to the bow of the fuselage, so that the hornbardier may at times act as a gunner in defending the forward part of the aircraft, it will be apparent in the course of the description hereinafter that the invention may be equally as well i employed in the defense of the aft portions of the aircraft.

Where .the gunner is stationed in the bow or 'stem of the fuselage, opportunity is afiorded to scan with the naked eye the field of view, since it is the general practice to have these portions of the aircraft furnished with transparent plastic material. Where the turret guns are positioned below the gunners station it becomes necessary then to supply some sort of sighting means which is coordinated with the movements of the guns in azimuth and elevation whereby the gunner may view the target field of the turret guns; since the gunner may easily follow the sight in azimuth and elevation with his head at the eyepiece of the sight, a simple and effective sighting arrangement is thus efiected.

A further desirable advantage in such a turret lies in havingthe control for the movements of the guns in azimuth and elevation arranged in such a manner that a measure of feel is given to the gunner in operation of the turret, i. e., to have increasing displacement of the control in any direction give increasing speed of travel of the guns and the sight in the same direction. For example, the movements of the control may be resolved into two components, viz., the movement about a vertical axis to ive azimuth movement to the guns, and the movement about a horizontal axis to give elevational movement to changing a circuit controlling the speed of the respond to movement of the control being of As explained above, giving increased displacements of the control about these axes guns for both the normal tracking speeds required and the'slewing speeds whereby the gunner may keep the target ship fixed within the sight.

The successful tracking of a target is dependent upon the operators ability to control the angular velocity of the guns without their being influenced by factors such as wind loads, frictional loads andrecoil forces. The new and improved turret accordingly makes use of a control in circuit having therein a pair of motor-generator sets or motor-amplidynes for furnishing current to the azimuth and/or elevation drive motors of such value that, irrespective of the load factors on the guns, there will be maintained an angular l5 velocity of the guns according to the control handle position.

An important consideration in the design and placement of gun turretsincludes the provision of both automatic and mechanical stops or limits to prevent movement of the guns at the end of their permissible limit of travel in both azimuth and elevation. Thus, a turret mounted in the bow of the fuselage must be limited in its permissive azimuth travel, so that the guns will not point and fire into the engine nacelles and the wings. Similarly, the elevation travel of the guns is limited as desired. Necessary also with the provision of limits or stops is the requirement that the guns may travel only in the opposite direction when the limit in one direction has been reached, thereby insuring that noharm is done to the drive motors or any of the mechanical parts. i

The rapidity with which the turret guns can utmost importance in the defense of the aircraft, it is therefore desirable that the movement of the control effect an immediate movement of the guns, and, accordingly, a feature of the control lies in the fact that it has no dead spot" through whichit must be moved before'a movement of the guns is had.

With the foregoing problems in mind, it is an objector this invention to provide a power operated turret having a sight synchronized in its movements therewith, which will enable the gunner to follow the target" field with a minimum of effort on his part, the sight being movable in the same direction as the head and e yes of the gunner in following the target.

Another object is to Provide a novel control.

arrangement for the use of the gunner in laying the turret guns on the target.

A further object includes the provision of novel means for giving feel to the gunner in moving the guns in azimuth and elevation.

A still further object includes the. provision of a quickly operated controller adjustment whereby the gunner may move the guns at moderate tracking speeds or at high orslewing tracking speeds.

Yet another object is to provide a novel control for an aircraft turret wherein the displacement of the controller is a function of the angular speed of the guns in azimuth and elevation.

Another object is to provide a controller characterized by the absence of a dead spot, so that as soon as an initial displacement of the controller is had, there will be an immediate tracking movement of the guns in azimuth or elevation or in combination of the two.

A still further object of the invention comprehends the use of motor-generator sets or motor-amplidyne sets for speed control of the azimuth and elevation drive motors whereby their speed may be accurately controlled regardless of the various load factors to which the guns are subjected.

.A yet further object of the invention includes the provision of mechanical and electrical means to limit the angular travel of the guns.

Still another object includes the provision of novel means for insuring that the guns must travel in the opposite direction when the guns have reached the mechanical limit of travel in one direction, thereby insuring against injury to the guns and the turret mechanism.

A yet further object is to provide dynamic braking to the guns as they reach their limit of angular travel. so that they will-not coast into the mechanical stops. I

While the invention is disclosed with reference to its employment in the bow of the fuselage, it will be obvious that features of the invention are not limited tothe use shown, the speed control system and the controller being readily adapted to the turrets disclosed in Pontius ap-' plication Serial No. 391,911, filed May 5, 1941, 45 Pontius application Serial No. 429,439, filed Febman: 4, 1942, and Kuzmitz et al. application Serial No. 471,124, filed January 2,. 1943. It is to be distinctly understood, also, that the invention is not limited otherwise than by the ap- 50 pended claims.

In the drawings which show a preferred embodiment of the invention: 4

Figure 1 is a longitudinal section of an airplane fuselage near the bow thereof, certain of 55 the elements forming a part of the inventionbeing shown in elevation;

Figure 2 is a schematic, isometric view of the turret showing the mechanical parts and movements, and showing schematically the motorgenerator or motor-amplidyne sets for supplying current to the drive motors;

Figure 3 is a plan view of the sight shown in I Figure 1;

Figure 4 is an elevation view ,of the sight shown 05 in Figure 3 looking toward the opposite side from that seen in Figure 1;

Figure 5 is an enlarged section taken along the lines 5--5 in Figure 4;

Figure 6 is an elevation view of the controller looking from the right in Figure 1;

Figure 7 is an enlarged view of the controller support arm shown in Figure 1;

Figure 8 is a section taken along the lines 9-8 in Figure 6; 70

. 4 Figure 9 is a view partly in section, and partly in elevation along the lines 8--8 of Figure 8.

Figure 10 is a view taken along the lines I0I0 of Figure 9, showing details of the controller seen in Figure 1;

Figure 11 is a section taken substantially along the lines I I-I i in Figure 9; and

Figure 12 is'a schematic diagram for the control circuit of the turret shown in Figure 1.

Referring now to Figure 1 of the drawings, a fuselage I00 of an airplane supports a turret I02 which has mounted therein guns I04 which are arranged to rotate with the turret I02 in azimuth and to rotate with respect to turret I02 in elevation. A seat I05 is slidably mounted atop the turret I02 so that a gunner-bombardier may adjust his position to operate the turret M2 or a bomb-sight (not shown) mounted in the extreme forward portion of the fuselage I00,

A controller I08, supported on arm I08 pivoted at 0 is adapted to be operated by the gunner.

for moving the turret, or to be moved to one side of the fuselage I00 out of the gunners way. when he is operating the bomb-sight. As will be described with particularity later, the

controller I08 pivots about II2 for controlling the movement of guns I04 in azimuth, controller I08 being so arranged that increasing angular displacement about axis II2 gives increasingangular tracking speed of the guns I04.

A pair of handles II4 (one being shown) are mounted on a shaft H8 and rotate with respect to the controller I08 for controlling the elevation movement of the guns I04, handles II4 being so arrangedthat clockwise rotation causes up-- ward movement of the guns I04 in elevation and counter-clockwise rotation causes downward movement of the guns I04 in elevation. Handles II4 are also arranged that increasing angular displacement both in a clockwise and a counterclockwise direction gives increasing tracking speeds to the guns I04 in elevation either up or down.

For giving high tracking or slewing speeds in both azimuth and elevation a high speed switch H5 is provided which may be closed at the will of the gunner.

A dead man control is provided for the controller I08 consisting of a switch II8 which is opened when the gunner grasps control handles II4. Switch II8 controls the flow of all current to the control circuit for the drive motors ofthe turret I02. so that the turret I02 may not be operated excepting under the control of the gunner.

A sight I20 15 provided for the gunner to observe the field of fire of the guns I04, and is synchronized with the movements of the guns I04 both in azimuth and elevation. Sight I20 is held in a mounting bracket I22 which is so arranged that it may rotate about axis I24 in synchronism with the elevation movements of the guns I04 and about a second axis I28 in synchronism with the azimuth movements of theguns I04.

Referring to Figure 2, turret I02 is supported within the fuselage I00 by a four-arm spider I28, the extermities of which are fastened to the fuselage I00 in any convenient manner. Adapted to rotate at the center of spider I28, and supported thereby, is a center column I30 which has secured near the top thereof a worm-wheel I32 which is driven by a worm I34 suitably connected as by a gear train I38 to an azimuth drive motor I 38.

placement of controlier IIIt.

For eflecting the azimuth movement of the sight I20 in synchronism with the azimuth movement of the center column I30 of the turret I02, a flexible shaft I38 is connected to the gear train I35.

Depending from the lower end of column I30 I are the guns I04, which are driven in elevation for exciting an exciter field of azimuth motoramplidyne set I82, as will be more fully described by a drive motor I 30, which through gear trains 1 I82 and Ida efiectrotative movement to a shaft I56 at the ends of which are mounted the guns I08 for corresponding elevation movement.

For effecting the elevation movement of the moving the guns I Reference will be had later to Figur'el2 for detail of the circuit for controlling the drive motors I36 and M5. the motorgenerator sets I50 and I52 in response to the dis- The details of sight I20 are shown in Figure 4, and as shown, sight I20=is mounted at the lower and forward end of bracket I22. Sight I 20 includes a lamp housing Id which supports a lamp I55 therein whose rays impinge against a reticle I53 of any desired pattern, as for example, a circle. Rays which pass the reticle I58 are reflected from a mirror surface I50 upwardly past a collimating lens'system I62, ltd, whence they are reflected from a second mirror I85 into the eye of the gunner. Mirror I65 is of the fractionally illuminized type, i. e., it reflects the reference pattern passed by the reticle I58 and transmits through'itself light rays from the target field view by the gunner or bombardier.

For moving the sight I20 in synchronism with the movement of the guns I06 in elevation, the mounting bracket I22 is pivoted about I 24 and has in the circular periphery thereof external gear teeth I58 which mesh with a pinion I70 (Figures 4 and'5), which is driven by a worm IIZ mounted at the end of the flexible shaft I68, and a worm wheel III.

Similarly, for moving the sight I20 in'synchronism with the movement of the guns I05 in azimuth, the mounting bracket I22 is journalled at I24 in a yoke I16 which'is pivoted at I26. Yoke 178 is provided with a gear sector III) which meshes with a pinion I80 driven by flexible shaft I38 through a worm I82 mounted at the end thereof, and a worm wheel I86, to effect rotation of the yoke I76 and the sight I 20 about pivot point I26 in synchronism with the azimuth movements of the guns IOI.

It will be seen, therefore, that the assembly just described gives synchronized'movement of the sight I20 with the movement of the guns I06 in both azimuth and elevation.

The details of controller I06 will best be understood with reference to Figures 6 to 11 inclusive. Controller I06 is secured to control support arm I08 by means of a union 200. which threadably engages a support member 202 of the controller A pair of control potentiometers 328 and 330 with reference to Figure 12. For changing the position of wiper arms 33% and 030, as the control I06 moves about vertical axis IIZ, a stationary vertical shaft 205 is provided which has mounted at one end thereof a gear sector 206 which driveably .engages a pinion 20d mounted on a shaft 2H3 which rotates therewith. Gear sector 2 06is secured to shaft 20% by a set screw 209. Wiper arms 33d and 336 are mounted on the shaft 2m to rotate therewith, and it will be seen that as the control I06 is shifted angularly about the pivot M2, the wiper arms 38d and are move with respect to the potentiometers 328 and 33d.

For returning the control I06 to neutral position, and for moving the control I06 angularly against a small force to give a measure of feel" to the gunner to a coiledspring 2H2 is mounted around shaft 20 1?, the ends rid of which are held against movement in the neutral position by means of adjusting-screws ZIS threaded into the body of control I 06. As the control its rocks is similarly provided with a spring as shown inabout axis II? the gear sector Edd will tend to coil spring 2I2 about the shaft 2% thereby increasing the force necessary to displace control I06 about axis II2.

Means are provided to prevent the travel of' control Hit about axis H2 beyond a position where injury to the potentiometer-s 328 and 33d and the control I06 might occur. As shown in Figure 10, gear sector 208 is provided with a pair of ears 205 which engage stops 2t? adjustably threaded into the body of controller I d6.

Elevation movement of the guns Idfl is effected by moving handles I III about their axis I It. Rotation of handles IId efiects rotation of a gear sector 2m which driveably engages a pinion 220 mounted on a shaft 222 which carries a pair of potentiometer wiper arms'dttl and 3% which contact a pair of potentiometer winding 52d and I30. In asimilar fashion to wiper arms 33 i and 336, wiper arms IM and 6136 pickoir a voltage difierential which is applied to the elevation motor-amplidyne set I50, as is more particularly described with reference to Figure 12.

For giving feel to the gunner, gear sector ZId Figure 11, and for preventing movement in'eiocess of a desired amount of the controller handles IId, gear sector no is provided with adjustable stops similar to those shown in Figure 10.

The control of the guns 80% both in azimuth I and elevation will best be understood with reference to Figure 12 which; is a schematic diagram are held fixedly in the controller I06 and are of the circuit controlling the azimuth andelevation motor-amplidyne sets I52 and I5@, azimuth and elevation drive motors I36 and Ili. controller I06 is shown schematically also in its relation to the control circuit of Figure 12.

A source 306 is provided to furnish power to the azimuth and elevation drive motors I38 and its and to the azimuth and elevation motoramplldyne sets I52 and IE0 through a power relay 302 by closing a'mainpower switch 39% which energizes the winding of relay 302 through conduit 306. Passing current through conduit 80% at the same time passes current through a conduit 308 to energize the field of azimuth drive motor I36. The closing of switch 306 at the time passes current to a lead em to energize the field winding of elevationdrlve motor M0.

Simultaneously with the closing of the power relay-8M is the passing of current through lead @IZ to the motor of the elevation motor-amplicontrol circuit of Figure guns I04 are not moved except when the control windings of the drive motors I36 and I40,

armatu'res thereof are immediately dynamically braked. namic brakin of the drive motors I36 and I40 I60. Similarly. with the closing or power is passed to the motor of the dyne set v relay 302 current azimuth motor-amplidyne at I62 through a lead 3. It will be seen, then, that as long as the main power switch 304 is closed the motor-amplidyne sets or motor-generator sets I60 and I62 will operate continuously, and, as will be criplained hereinafter, the output of the generator or amplidyne side of sets I60 and I62 will vary.

- thereon is shown in Figure 1, safety means are incorporated into the 12 to insure that the handle II4 of Figure 1 is grasped. Safety swi ches H6 of Figure 1 are shown schematically in Figure 12, the left switch of the pair of switches II6 being the one mounted in theleft one of the pair of control handles II4 of Figure l. Switches IIO are normally closed, i. e, when the gunner does not grasp either of control handles H4, so that the armatures of the drive motors I36 and I40 are disconnected from the output side of the motor-amplidyne sets I62 and I60, and the armatures thereof are shorted; and since the armaturesare in a strong field furnished by the fiellld t e Controller I06 is so arranged that dyis effected only when neither of the control han- -,dles is grasped by the-operator or gunner. Since the dead man switches I I0 are of the normally the control handles I I4 is grasped, dynamic braking will not occur until both hands are freed from the controller handles H4. The circuit for effecting dynamic braking when the control handles are freed by the gunner is as follows. Current is supplied by lead 3 to switch group I I0 whence it passes out a lead 3I6'to energize a winding 3I3 of an azimuth dynamic braking relay 320. Similarly, current is passed out of switch group II3 by a lead 322 to energize a windin 324 of an elevation dynamic braking relay 320.

to the controller m, that as controller m is 'closed type. opening only when one or both of It will be noted that when windings 3I3 and 324 are energized, the armatures of relays 320 and 320 are attracted downwardly, thereby shorting the armatures of drive motors I30 and I40. It may be noted that when the armatures of relays 320 and 326 are attracted downwardly, the cur-' rent supplied by the output'sides of motor-generator sets I62 and I60 is thus cut off from the armatures of drive motors I30 and I40. I

Tracking speeds for the drive motors I36 and I40 are selected in accordance with the position of the controller I06 shown in Figure 1. Moving controller I06 about axis II2 to the right or clockwise, for example, causes guns I04 to move to the right or clockwise. Increased angular displacement of the controller I00 about axis II2 clockwise, causes the tracking speed in azimuth clockwise to increase. It will be seen, therefore, that speed of the guns I04, is a function of the position of controller I06.

Similarly, movement of controller handles 1 I4 in a clockwise direction as viewed in Figure 1, causes guns I04 to move up in elevation, and the of azimuth drive motor I30, and starts the azimuth motor-amplidyne set I62. Closing main power switch- 304 also energizes the pair of azimuth control potentiometers 323 and 330 (shown in Figures 8 and 9) through a conductor 332 The pair of potentiometer wiper arms 334 and 330 (shown In Figures 8 and 9) are so linked displaced angulariy to the right, or clockwise, the potentiometer wiper arms 334 and 336 are moved to the right asshown in Figure 12. As

the controller I00 is moved from the neutral position as shown in Figures 1 and 12 in a clockwise direction, wiper arm 334 moves toward the positive end of 3, otentiometer 320 and wiper arm 3.30 moves toward the negative end of potentiometer 330. The voltage that exists across wiper arms 334 and 330 is thus a function of the position of controller I06 and is applied by a pair of leads 338 and 340 to an exciter field 342 of the amplidyne side of motor-amplidyne set I62. Voltages thus applied to the exciter field 342 cause the amplidyne side of motor-amplidyne set I62 to generate an output voltage across a pair of leads 34 4 and 340 which is proportional to the exciter voltage applied to field 342, and several times the voltage across wiper arms 334 and 336. However, the power input to the exciter field 342 may never exceed one watt while the output power of the motor amplidyne I62 may be several 7 connected by lead 338 to the exciter field 342.

However, wiper arm 336 is connected to exciter field 342 not only through lead 340 but also through a resistor circuit consisting of resistors 340, 360, and a part of resistor 352. As soon as the voltage across leads 344 and 346 begins to rise, the voltage across resistor 360 and the bottom part of resistor 362 opposes the voltage from the wiper arms 334 and 336, thus reducing the current to exciter field 342. A stable'point of balance is thus immediately reached.

It will be seen that when the output voltage ,of the amplidyne side of motor-amplidyne set I62 is lowered because of increased load on azimuth drive motor I36, the opposing voltage across resistor 350 and the bottom part of resistor 362 decreases, and more current flows to the exciter field 342. Conversely, if the output voltage from the amplidyne side of motor-amplidyne speed will be a function of the controller handle v position.

For giving the increased tracking speeds of the guns I04 according to the angular displacement of the controller I06 without. the tracking speeds set I62 increases, because of lighter loads on azimuth drive motor I36, the opposing voltage across resistor 360 and the bottom part of resistor 362 increases. This tends to keep the output voltage constant, regardless of load on azimuth drive motor I36, for any given position of the controller I06.

When a load is applied to the drive motor I36,

it. tends to slow down, at the same time dra more current from motor-amplichrne set I82. This current flows through lead 866 through the dynamic braking relay 320 and through resistor 3A8, causing a voltage drop therein. Since.

resistor 348 is'in the circuit for wiper am 338, this voltage drop is added to the voltag from wiper arms 336 and 334, bringing the amplidyne output voltage up, and it thereby brings the speed of motor I36 back to its no-load value.

Forobtaining high tracking or slewing sp eds of the guns We in azimuth, means are provided in the control circuit just described for-obtaining high output voltages from the motor-amplidyne set I52 for the azimuth drive motor I38. .Closing either one of the pair of high speed switches H5 of Figures 1 and 12 passes current from lead 3M through one or both of switches I IE to a lead 358 and thenceto a relay 356. When the left of the pair of armatures associated with relay 35d moves to the right, resistor set, which furnishes part of the'opposing' voltage, is shorted out. Current flowing in lead 360 then takes a path through lead 3%, through the left-hand armature of relay 3%, through lead 358 and directly to the bottom part of resistor 352. .At such timethe voltage supplied by wiper arms 33d and 836 is not opposed by as great a voltage as part of the resistor circuit has been shorted out, and, therefore the voltage supplied to exciter field 332 is correspondingly increased.

For the purpose of. cancelling any excitation of the amplidyne, including the excitation due to residual magnetism, thus bringing the amplidyne output voltage down to zero when dynamic braking is applied to drive motor let, an anti-shunt field for the motor-amplidyne set 552 is provided. Switches He are of the normally closed type, closing when the gunner does not grasp controller handles us. At such times asraiie fi arms 8 86 and 336 with respect to each other,

i there can be no possibility that-the failure of the amplidyne output polarity, and thus direction of azimuth drive motor I36, to change immediately as the polarity of the wiper arms 334 and 336 changes will cause the guns I04 to be driven through the clockwise mechanical limitations of travel because of selection of the wrong limit switch 868' or 368.

'. Means are provided for eliminating deadspots on the controller I06. It. will be seen inv Figure 12 that potentiometer 330 is divided at ate and-controllable voltage across wiper arms" 33% and 3364s set up.

While the operation and control of the spec of azimuth motor ltd has been described for efiecting clockwisemotion'of the guns we in azimuth, it will be seen-that to effect counterclockwise movement of the guns we in azimuth, the wiper arms 33% and 336 will move to the left.

This movement will reverse the current in the exciting held 362 and will reverse the current outputon the amplidyne side of azimuth motoramplidyne set 852. I

The operation of the azimuth drive system has been described with particularity, and the elevaas both of switches its are closed, winding Sid into lead 380 through a current -limiting resistor 362' and thence to an anti-shunt field 3%, which furnishes a field opposite in direction to the as follows:

other fieldsof amplidyne I52, and thehce to Limit switch 366 in conjunction with a limitselector switch 372, prevents clockwise rotation beyond a predetermined limit when controller are igdisplaced to give clockwise movement of the guns in',azimuth, and when bothare closed energizes dynamic braking relay 320. The circuit for effecting dynamic braking is made through lead 832, adjacent a pair of limit selector switches 310 and 312, a lead 3M through clockwise limit switch 366 and thence to winding 3l8 of relay 320 through lead 3l6. Limit selector switches are moved with the controller I06 and overlap, so that when the controller I06 is going through the neutral pcsition to eiiect movement of the guns in the opposite direction, i. e., while the controller is changing the polarity of wiper tion drive system is similar in operation. For the sake of brevity, however, detailed description of the elevation drive has been omitted, but parts corresponding to the parts of the electrical system on the azimuth drive have been given ordinals corresponding to those in azimuth, except that the ordinals are in the 400 series.

The above-described circuit which is not basically or broadly of our invention as a control of general application, but which involves features of novelty in the described combination, for the purposes of convenience and succinctness in the claims is called motor-generator means."

The operation of the turret described above The gunner or bombardier occupies seat W5 which he may slide forward so that he can grasp Jcontroller we at the control handles lid and at the same time mer through sight ltd at its eyepiece. Closing the main power switch 3% passes current to the motor-amplidyne sets E50 and 552 and the field windings of drive motors are and i til,

placing them in a "make-ready condition to receive control voltages from the controller we similar manner the counterclockwise rotation in' azimuth of guns ms. 7

By moving controller handles Wt clockw se about their axes us the guns we will be e ed upward in elevation about shaft 168 (Figu e 2').

As in the case with the azimuth movement of the guns I04, increasing tracking speed is efiected by increasing the displacement of controller handles H4 about axes H6, counterclockwise rotation of the controller handles ilt causes the pended.

nuth and elevation movements of guns I! through the medium of sight drive cahles'llfl and I48, the gunner may observe the target field of the guns as. they swing in azimuth and elevation; or conversely, havhig kept the sight I20 on the target, his guns will also be. trained on the target.

' Any convenient means may be emplr-ved for firing the guns I04 when they are trained onthe target, as for example as shown in Pontius application Serial No. 391.911, filed May 5. 1941, and Pontius et al. application Serial No. 489,622, filed April 20, 1942. A firing switch for the guns IM may be conveniently mounted in each of the controller handles II. or any other convenient place according to esigners choice.

For giving increased tracking or slewing speeds the gunner closes one of the high speed switches mounted in controller handle 4, and then the high tracking speeds may be varied according to the angular displacement of control I08 and control handles III.

As has been explained with reference to Figure 12, when the guns I04 reach their mechanical limit of travel in azimuth and elevation drive for changing the exciting field when an increase in the tracking speed is desired for any given position of the control from neutral, limit selector switch means associated with said control and arranged to respond to movement or said controller for limiting the movement of said gun, said limit means including conductors and a relaycontrolled switchconnected' to each of said power means for dynamically braking said power means.

2. A turret for use in the bow or stern portions of an aircraft or the like comprising, in combination, a turret member, a mounting for said turret member carried by said aircraft, a gun mounted on said turret member for rotation therewith in azimuth and constructed and arranged to roi 1 tate with respect to said turret member in elevamotors I36 and I40 are immediatelydynamically braked. The gunner then is able to move the uns in the opposite direction only, which he does by reversing the direction of movement of control I06 and controller handles Ill.

While the invention has been described with reference to a preferred embodiment it is to be understood that the; invention is not limited in scope except by the claims which are hereto ap- -We claim:

1. A turret for use in the bow or stem portions of an aircraft or the like comprising, in combination, a turret member, a mounting for said turret member carried by said aircraft, a gun mounted on said turret,member for rotation therewith in azimuth and constructed and arranged to rotate with respect to said turret member in elevation, a sight synchronized in itsmovements with the azimuthal and elevational movement of said gun and constructed and arrangedto enable a gunner peering into the said sight to observe the field of fire of the gun, means including a pair of flexible cables connecting said turret member and gun to said sight to impart movement thereto corresponding to movement of the gun, power means for rotating said turret member with the gun in azimuth, motor generator tion, a sight synchronized in its movements with the azimuthal and elevational movement of said gun and constructed and arranged to enable a gunner peering into said sight to observe the field of fire of the gun, means including a pair of flexible cables connecting said turret member and gun to said sight to impart movement thereto, power means for rotating said turret member with the gun in azimuth, motor generator means for supplying voltage and current to said power means in accordance with load and desired speed, a separately excited winding on the generator for furnishing an exciting field therefor, power means- .for rotating said gun in elevation, a second motor generator means for supplying voltage and ourrent to the elevational power means in accordance with load and desired speed, a separately excited winding on said second-named generator for furnishing an exciting field therefor, and

control means for both of said power means including a manually operated controller rotatable about a plurality of axes angularly displaced with respect to each other, said controller being nor- 40 mally held in a neutral position on said axes and constructed and arranged so that rotation from neutral in any direction about said axes selects the gun for corresponding movement in the selected direction, the angular displacement of said controller'from neutral determines the tracking speed of the gun, said control means including a switch to be closed for changing the exciting field when an increase in tracking speed is desired for any given position of the control from neutral, limit selector, switch means associated with said control and arranged to respond to movement of said controller for limiting the movement of said gun, said limit means including conductors and a relay-controlled switch conmeans for supplying voltage and current to said power means in accordance with load and desired speed, a separately excited winding on the generator for furnishing an exciting field therefor, power means for rotating said gun in elevation, a second motor generator means for supplying voltage and current to the elevation power means in accordance with load and desired speed, a separately excited winding on Y said secondnamed generator for furnishing an exciting field therefor, and control means for both of said power means includinga manually operated coning movement in the selected direction, said control'means also including a switch to be closed nected to each .of said power means for dynamically braking said power means.

3. A turret for aircraft or the like comprising a turret member, a mounting for said turret member carried by said aircraft, a gun mounted on said turret member for rotation therewith in azimuth and arranged for rotation with respect thereto in elevation, power means for rotating said turret member with the gun in azimuth, motor generator means for supplying voltage and current to said power means in accordance with load and desired speed, a separately excited winding on the generator for furnishing an exciting field therefor, power means for rotating said gun in elevation, a second motor generator means for supplying voltage and current to the elevational power means in accordance with load and desired speed, a separately excited winding on said second-named generator for furnishing an exciting field therefor, and control means for both of said power means including a manually I operated controller rotatable about a plurality of axes angularly displaced with respect to each other, said controller being normally held in a neutral position on said axes and constructed and arranged so that rotation from neutral in any direction about said axes selects the gun for corresponding movement in the selected direction, said control means including a switch to be closed for changing the exciting field when an increase in the tracking speed is desired for any given position of the control from neutral, limit selector switch means associated with said control and arranged to respond to movement of said controller for limiting the movement of said gun in the dire ion selected, said limit means including conductors and a relay-controlled switch connected to each of said power means for dynamically braking said power means.

4. A turret for aircraft or the like comprising a turret member, a mounting for said turret member carried by said aircraft. a gunmounted on said turret member for rotation therewith in azimuth and arranged for rotation with respect thereto in elevation, power means for rotating said turret member with the gun in azimuth, motor generator means for supplying voltage and current to said power means in accordance with load and desired speed, a separately excited winding on the generator for furnishing an exciting field therefor, power means for rotating said gun in elevation, a second motor generator means for supplying voltage and current to the elevational power means in accordance with load and de-, sired speed, a separately excited winding on said, second-named generator for furnishing an exciting field therefor, and control means for both of said power means including a manually operated controller rotatable about a plurality of axes angularly displaced with respect to each other, said controller being normally held in a neutral position on said axes and constructed and arranged so that rotation from neutral in any direction about said axes selectstthe gun for corresponding movement in the selected direction, the angular displacement of said controller from neutral determines the tracking, speed of 

